1. Field of the Invention
The present invention relates generally to an alternating current power distribution system, and in particular to an alternating current power distribution system supplied alternatively from a line alternating current power source and from a backup direct current power source.
2. Description of the Prior Art
There exists in the prior art a multitude of a-c power systems having alternate source of supply capability. The conventional method employed by such systems includes utilizing a ferro resonant voltage regulator circuit to couple a-c power to a load with control circuitry for sensing voltage outages and supplying an alternate source of a-c power to a load during such voltage outages.
A major disadvantage of the conventional systems are that such systems utilize flux coupling in the ferro resonant voltage regulator circuit to couple the a-c power to the load. Thus, a switch is required to disconnect the a-c line power source from the ferro resonant voltage regulator circuit when the alternate source of a-c power is energized because the ferro resonant voltage regulator circuit will reflect the a-c power generated by the alternate source of a-c power through the voltage regulator circuit to the a-c line power source.